Solder wire is usually used together with an electric soldering iron. When using it, pay attention to the following issues:
1. When setting the temperature of the soldering iron tip, the heat resistance and safety of electronic components should be considered. If necessary, a constant temperature electric soldering iron should be used to make the welding temperature continuous and durable. In this way, the welding effect of lead-free solder wire is better . After the soldering operation, the lead-free soldering iron tip and the sleeve still need a period of time to cool down, and the solder joints and the electronic components to be soldered are still very hot. Please do not touch them with your hands to prevent burns.
2. Use authentic lead-free soldering iron tips matched with the manufacturer, counterfeit or poor-quality lead-free soldering iron tips, with different hole sizes and different casing thicknesses. These conditions will cause unstable performance of the lead-free electric soldering iron, resulting in Faults and shorten the service life of the soldering iron.
3. Use a thermometer to measure the temperature of the soldering iron tip before welding. The temperature at the tip of the soldering iron tip is very high, as high as 300 °C or more, and the soldering personnel should be careful to be scalded! The welding action should be fast to avoid excessive heat from being introduced into the pad of the circuit board to cause burning of the board.
When soldering with an electric soldering iron, according to the size of the weldment, the power and type of the soldering iron, the type and diameter of the solder wire, the temperature should be the melting point of the solder plus about 150°C.
1. How to hold the soldering iron: (1) low-temperature soldering iron: hold a pen to write; (2) high-temperature soldering iron: grasp with fingers downward.
2. The ideal angle between the tip of the soldering iron and the PCB is 45°C.
3. The tip of the soldering iron should be kept clean.
4. It is strictly forbidden to touch the heating element of the soldering iron with your hands when using it.
5. It is strictly forbidden to use the soldering iron violently (such as hitting hard objects with the tip of the soldering iron, etc.
Due to improper process, the following problems are often prone to occur when solder wire is used for welding:
1. Icicle (pointed)
Reasons: (1) uneven temperature conduction; (2) poor solderability of PCB or parts; (3) large deviation of solder composition.
2. Poor wetting
Reasons: (1) External pollution; (2) Insufficient tin wire flux activity (3). Rosin is broken inside the tin wire; (4) Serious oxidation of components
3. Solder ball
Reasons: (1) The water content in the tin wire flux is too high; (2) The flux in the tin wire is not continuous.
4. Cold welding.
(1) The temperature of the soldering iron is too low; (2) The soldering time is short.
5. Surface quality of solder joints
(1) The welding temperature has a great influence on the brightness of the solder joint. Insufficient temperature will reduce the gloss of the solder joint surface and make it not smooth. Experiments have proved that the brightness of soldering the same tin wire with a 20w soldering iron and a 60w soldering iron is different.
(2) The brightness of the solder flux used in the tin wire of the same degree is different when the type is different, because the different substances contained in the active agent have an impact on the brightness of the solder joint.
(3) When the tin content of the tin wire deviates, the brightness will be affected, but in general, the tin content within 5°C can be separated. When the content deviation of impurities is large, the brightness of solder joints will also have a more obvious impact, such as copper, silver, bismuth and so on.
When using lead-free solder wire, the tip of the soldering iron is consumed quickly. The reason is that the material of the tip of the soldering iron is mainly iron or copper, which reacts with the solder. Using lead-free solder, the solder composition changes from 60% tin to almost pure tin, and the probability of reaction increases. In addition, lead-free solder has a high melting point and poor wettability. In this way, The loss of the soldering iron tip will naturally increase a lot. Therefore, some manufacturers use special corrosion-resistant lead-free soldering iron tips.
